Multi-electrode apposition judgment using pressure elements

Abstract

Apparatus and methods for determining positioning of a energy delivery element include deploying a energy delivery element at a treatment site proximal to a vessel wall; using a multi-region pressure sensing apparatus to sense pressures applied in a plurality of directions about the energy delivery element; and determining an orientation of the energy delivery element based on the pressures measured in the plurality of directions about the energy delivery element.

What is claimed is: 
     
       1. A system, comprising:
 an intravascular catheter comprising an elongated shaft having a proximal portion and a distal portion configured for intravascular insertion into a body lumen of a human patient; 
 a therapeutic assembly carried by the distal portion of the shaft, the therapeutic assembly including— 
 an energy delivery element configured to deliver energy to modulate nerves associated with sympathetic neural function; 
 a cylindrical capacitive sensor configured to measure contact force against a wall of the body lumen, the sensor being disposed at or proximate to the energy delivery element, the cylindrical capacitive sensor having a plurality of regions that are circumferentially separated by one or more non-conductive areas; and 
 a controller operably connected to the energy delivery element and the cylindrical capacitive sensor, the controller configured to— 
 obtain a plurality of contact force measurements corresponding individually to the plurality of regions; and 
 determine an orientation of the energy delivery element relative to the wall of the body lumen based on at least one of the plurality of contact force measurements. 
 
     
     
       2. The system of  claim 1  wherein the cylindrical capacitive sensor device comprises:
 a first conductive annular ring; and 
 a second conductive annular ring disposed coaxially with the first conductive annular ring; 
 wherein the one or more of non-conductive areas are disposed on the second conductive ring. 
 
     
     
       3. The system of  claim 1  wherein the cylindrical capacitive sensor includes a plurality of capacitive elements that individually correspond to the plurality of regions. 
     
     
       4. The system of  claim 1  wherein the cylindrical capacitive sensor is axially disposed on either side of the energy delivery element. 
     
     
       5. The system of  claim 1  wherein the cylindrical capacitive sensor is positioned adjacent to the energy delivery element along the distal portion of the shaft. 
     
     
       6. The system of  claim 1  wherein the system further includes a plurality of cylindrical capacitive sensors and a plurality of energy delivery elements, and wherein the cylindrical capacitive sensors are interposed between adjacent energy delivery elements along the distal portion of the shaft. 
     
     
       7. The system of  claim 1 , wherein the distal shaft portion is configured to take a pre-determined shape upon deployment in the body lumen;
 wherein the energy delivery element is disposed in a predetermined radial orientation on the distal shaft portion, and 
 wherein the plurality of sensor regions is configured to sense contact force in a plurality of radial directions about the distal shaft portion. 
 
     
     
       8. The system of  claim 7 , wherein the distal shaft portion is a shape set element. 
     
     
       9. The system of  claim 7 , wherein the distal shaft portion is shape set in a helical geometry.